Compact C-shaped MIMO diversity antenna for quad band applications with hexagonal stub for isolation improvement

A compact MIMO antenna was proposed in this article. The designed antenna is compact in size with dimensions of 20 x 34 x 1.6 mm. In this proposed antenna model the patch consisting of two counter facing C-shaped elements facing each other in which a hexagonal ring attached to a strip line which is placed in between the two C-shaped patch acts as the stub. The novelty of the antenna elements lies isolation improvement by using the ground stub with the use of circular ring resonator. The proposed antenna operates in four bands in which 2.66 to 3.60 GHz (Wi-Max, Wi-Fi), 4.52 to 5.78 GHz (WLAN), 6.59 to 7.40 GHz (satellite communication), and 9.55 to 10.91 GHz and having bandwidth of 0.94, 1.26, 0.81, and 1.36 GHz at four bands. The envelope correlation coefficient is ECC <= 0.3 and diversity gain > 9.8 dB for the operating bands of antenna proposed. This antenna can work in the bands of Wi-Max, Wi-Fi, WLAN, satellite communication in X-band and for radio location, and astronomy applications.